The soap opera battle to elect Haiti's next president has taken another unlikely twist after the ruling Unity party withdrew backing for its candidate Jude Célestin, one of three contenders who had been due to contest a final run-off election in the coming weeks.

Saying that it "does not want the people to suffer any more", the party hopes its move will avoid further unrest and clear the way for a showdown between the two remaining candidates: the country's former first lady, Mirlande Manigat, and Michel Martelly, a popular singer.

Mr Célestin, the preferred successor of Haiti's current President, Rene Preval, had been at the centre of controversy since November's chaotic first round of voting, when he unexpectedly pipped Mr Martelly to second place. The shock result sparked rioting and widespread allegations of voter fraud.

A report by the Organisation of American States (OAS) found irregularities in voter returns, and recommended that Mr Célestin be replaced by Mr Martelly in the run-off. International observers, including the UN, US and UK, put pressure on Mr Célestin and Unity to withdraw. The party said in a statement: "We chose not to provoke the international community over the election. We thank Jude for understanding the situation, though neither he nor we agree with the way things have occurred."

Many observers said the decision was a rare outbreak of sanity in a country with a history of political chaos. But not everyone: the Washington-based Center for Economic and Policy Research is one of several organisations who are calling for all three candidates to contest a properly organised repeat of November's election.

Meanwhile, Mr Célestin could yet throw a spanner in the works by refusing to co-operate with his own party. Under the Haitian constitution, a candidate must sign his or her resignation papers; sources yesterday said he was refusing to put pen to paper.

Presuming Mr Célestin does eventually play ball, the troubled country which lost up to 300,000 people in last year's earthquake, will still be sharply divided at the eventual run-off election.

Ms Manigat, 70, a university law professor whose husband Leslie was ousted in a 1988 coup, is bidding to become the country first female leader. She is thought to have the backing of the business elite and many wealthy Haitians.

Mr Martelly, 49, can meanwhile count on the support of younger voters. The singer, who performs as "Sweet Mickey", presents himself as a "change" candidate with few ties to the country's often dubious political establishment.